This surprisingly grim follow-up to last year's dystopian near-future fantasy escapes the home-invasion confines of the original to take to the streets of the city, where chaos once again reigns. During an annual 12-hour free-for-all in which crime – including murder – is temporarily rendered legal, a bedraggled group find themselves huddled together in downtown LA where vigilante gangs, mysterious hitmen and wealthy scumbags wreak violent havoc.

The post-Rollerball/Hunger Games premise may not stand up to much scrutiny, but writer-director James DeMonaco keeps us distracted from the underlying silliness by taking class-war potshots at the ruling elite, whose barbarity (both fiscal and personal) proves the real theatre of hate. Despite the box-office success of The Purge (which DeMonaco envisaged as "a politically subversive indie that would play in small arthouses"), this sequel still resembles a nasty little B-picture, unashamed of its exploitation roots.